I've tried searching out a solution for this (these forums, other forums, Google) and I've come up dry. I'm starting to think what I'm trying to do isn't even possible?
Anyway, first, I'll describe my basic network setup:
I have my primary router (running firewall, DHCP, etc., but NOT running OpenVPN). The primary router feeds the Internet to the rest of my LAN. On the LAN I have several computers connected including an iTunes media server (just an old iMac). There's also a secondary router on the LAN running Tomato and OpenVPN client—this router has an Ethernet cable coming from the LAN port of the primary router and is plugged into the WAN port (on the Tomato router).
I use this for connecting to a third-party VPN server/service that allows me to be seen as being in the USA (I'm actually in Canada). The idea is I'd be able to plug an Apple TV into the Tomato router (with OpenVPN client connected to the third-party VPN service) so I can access Hulu Plus.
This is actually set up and working. But, I'm having the issue where the Apple TV is now isolated from the rest of the regular LAN and thus it can no longer access the iTunes media server (where is usually streams all my local content from).
Like I said, I've tried figuring this out on my own. And I'm by far no expert with Tomato (though, I've been running it on numerous routers for years) and OpenVPN (again, while I have experience with VPN servers/clients, I've never dealt with anything like this).
So, if anyone would be willing to lend me some advise/a helping hand, it'd be greatly appreciated!